Skip to content

Instantly share code, notes, and snippets.

@apolaskey
Last active March 25, 2026 02:23
Show Gist options
  • Select an option

  • Save apolaskey/53e177c19d0b640fdc130291b534dfdc to your computer and use it in GitHub Desktop.

Select an option

Save apolaskey/53e177c19d0b640fdc130291b534dfdc to your computer and use it in GitHub Desktop.
US 100% energy demand solar grid (thought experiment)

☀️ What If We Covered Every US Parking Lot in Solar Panels?

A rough-order-of-magnitude (ROM) estimate for replacing 100% of US electricity generation with solar canopies over parking lots, paired with distributed iron-air battery storage.


The Premise

  • Cover 4.4 million grocery-store-sized parking lots with solar canopies
  • Pair each lot with iron-air battery storage (3–4 shipping containers per lot)
  • Replace 100% of US electricity generation
  • Build it in 7 years

US Electricity Baseline

Metric Value
Annual consumption ~4,000 TWh
Average continuous demand ~450–500 GW
Peak demand (summer) ~700–750 GW

Per-Lot Design

Each grocery-store-sized parking lot (~1.5 acres, ~150–200 spaces) becomes a self-contained solar microgrid node.

Component Per Lot
Solar canopy nameplate capacity ~0.45 MW
Daily generation (25% capacity factor) ~2.7 MWh
Iron-air battery storage ~2.3 MWh
Battery footprint 3–4 shipping containers
Ground space used by batteries ~2% of lot

Build Cost (7-Year Rollout)

Costs reflect learning-curve reductions as production scales (~20–25% cost drop per cumulative doubling).

Component Cost
Solar canopies (2,000 GW) $3.4T
Iron-air batteries (10,000 GWh daily) $550B
Seasonal storage supplement (50,000 GWh) $300B
Power electronics / inverters $350B
Distribution grid upgrades (4.4M lots) $350B
Transmission upgrades (HVDC corridors) $300B
Grid modernization (controls, software, cyber) $75B
Engineering & program management $400B
Contingency (12%) $700B
TOTAL $6.4T

Annual spend during build: ~$915B/yr


Learning Curve Impact

Year Cumulative Build Solar $/W Iron-Air $/kWh Annual Lots Built
1–2 Ramp-up $2.50 $35 ~200K/yr
3–4 ~15% complete $2.10 $28 ~350K/yr
5–6 ~35% complete $1.75 $22 ~450K/yr
7 ~60–100% complete $1.30–1.50 $15–18 ~500K/yr

Without learning curves the program would cost ~$10.5T. Production efficiencies save ~$4T.


New Annual Energy Budget (Post-Build)

Item Annual Cost
Grid maintenance (existing + new) $125B
Solar canopy maintenance & cleaning $30B
Iron-air battery maintenance $20B
Battery replacement reserve (20-yr cycle) $40B
Grid operations, software & staffing $25B
TOTAL $240B/yr

Before vs. After

Metric Today After Build
Annual electricity cost $450B/yr $240B/yr
Annual fuel cost $200B/yr $0
CO₂ from electricity 1.6B tons/yr 0
Energy price volatility High Near zero
Annual savings $210B/yr

Key Program Stats

Metric Value
Total parking lots covered 4.4 million
Total build cost $6.4 trillion
Build timeline 7 years
Annual build spend ~$915B/yr
Post-build annual energy budget $240B/yr
Annual savings vs. today $210B/yr
Cost per US household ~$49K
Breakeven ~16–17 years post-build
50-year net savings (after payback) $5–6 trillion

Cost by State (Population Share)

Per capita cost: $19,137 · Per household: ~$47,843

State Est. Population State Share Per Capita
California 39,500,000 $755.9B $19,137
Texas 30,500,000 $583.7B $19,137
Florida 23,000,000 $440.2B $19,137
New York 19,500,000 $373.2B $19,137
Pennsylvania 12,800,000 $245.0B $19,137
Illinois 12,500,000 $239.2B $19,137
Ohio 11,800,000 $225.8B $19,137
Georgia 11,000,000 $210.5B $19,137
North Carolina 10,700,000 $204.8B $19,137
Michigan 10,000,000 $191.4B $19,137
New Jersey 9,300,000 $178.0B $19,137
Virginia 8,700,000 $166.5B $19,137
Washington 7,900,000 $151.2B $19,137
Arizona 7,400,000 $141.6B $19,137
Tennessee 7,100,000 $135.9B $19,137
Massachusetts 7,000,000 $134.0B $19,137
Indiana 6,800,000 $130.1B $19,137
Missouri 6,200,000 $118.6B $19,137
Maryland 6,200,000 $118.6B $19,137
Wisconsin 5,900,000 $112.9B $19,137
Colorado 5,900,000 $112.9B $19,137
Minnesota 5,700,000 $109.1B $19,137
South Carolina 5,400,000 $103.3B $19,137
Alabama 5,100,000 $97.6B $19,137
Louisiana 4,600,000 $88.0B $19,137
Kentucky 4,500,000 $86.1B $19,137
Oregon 4,300,000 $82.3B $19,137
Oklahoma 4,000,000 $76.5B $19,137
Connecticut 3,600,000 $68.9B $19,137
Utah 3,400,000 $65.1B $19,137
Iowa 3,200,000 $61.2B $19,137
Nevada 3,200,000 $61.2B $19,137
Arkansas 3,000,000 $57.4B $19,137
Mississippi 2,900,000 $55.5B $19,137
Kansas 2,900,000 $55.5B $19,137
New Mexico 2,100,000 $40.2B $19,137
Nebraska 2,000,000 $38.3B $19,137
Idaho 2,000,000 $38.3B $19,137
West Virginia 1,800,000 $34.4B $19,137
Hawaii 1,400,000 $26.8B $19,137
New Hampshire 1,400,000 $26.8B $19,137
Maine 1,400,000 $26.8B $19,137
Montana 1,100,000 $21.1B $19,137
Rhode Island 1,100,000 $21.1B $19,137
Delaware 1,000,000 $19.1B $19,137
South Dakota 900,000 $17.2B $19,137
North Dakota 800,000 $15.3B $19,137
Alaska 700,000 $13.4B $19,137
Vermont 650,000 $12.4B $19,137
Wyoming 580,000 $11.1B $19,137
TOTAL 334,430,000 $6.4T $19,137

Note: A pure population split is the simplest model. A more nuanced version could weight by state electricity consumption, solar resource quality, and existing grid infrastructure.


The 70% Alternative

Covering only 70% of US demand is arguably the sweet spot — skip the hardest, least-sunny sites and let existing gas, nuclear, hydro, and wind handle the rest.

Metric 100% Plan 70% Plan
Lots covered 4.4M 3.1M
Total build cost $6.4T $3.8T
Build timeline 7 years 7 years
Annual build spend ~$915B/yr ~$540B/yr
Post-build annual cost $240B/yr $110–125B/yr
Breakeven ~16–17 yrs ~12–14 yrs

Storage: Lithium-Ion vs. Iron-Air

Factor Lithium-Ion (LFP) Iron-Air
Energy density ~200 Wh/kg ~50 Wh/kg
Cost per kWh $150–200 $20–50
Round-trip efficiency ~90% ~45–50%
Cycle life 4,000–6,000 3,000+
Lifespan 10–15 years 20+ years
Material scarcity Constrained (lithium) Abundant (iron)
Best for Daily cycling Multi-day / seasonal

This plan uses iron-air for its low cost and material abundance, accepting the lower efficiency tradeoff.


TL;DR

The US has paved enough parking to power itself with solar. $6.4T over 7 years. Energy bill drops from $450B to $240B/yr. Pays for itself, then saves $210B/yr forever. And you never park in the sun again. ☀️🅿️


All figures are rough-order-of-magnitude estimates based on publicly available data and standard industry assumptions. Actual costs would vary based on regional factors, policy, supply chain conditions, and technology development.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment